Polycarboxylic acid high-performance water-reducing agent is a new type of high-performance water-reducing agent based on acrylic acid and grafted with different side chain lengths. It can minimize the water-binder ratio of concrete and achieve maximum fluidity. In addition to the functions of high efficiency water reduction, improvement of concrete pore structure and compactness, it can also control the slump loss of concrete, and better solve the problems of air entrainment and slow bleeding of concrete.
Polycarboxylic acid high-performance water-reducing agent is an ether type water-reducing agent, with good dispersibility and slump retention, and strong cement adaptability, so it is widely used. The water-reducing agent synthesized by HPEG polyether structure type is reasonable in cost, superior in performance, simple in operation, non-polluting in the production process, does not contain formaldehyde, meets the 1SO14000 environmental protection management international standard, and can replace cement with more slag or fly ash. Thereby reducing the cost of concrete, it is a green and environmentally friendly product with a broad market prospect.
Raw materials and instruments
Raw materials for this experiment: HPEG modified polyether (molecular weight 2400), industrial grade; acrylic acid (purity 99%), industrial grade; initiators A, B and chain transfer agents C, D; sodium hydroxide, industrial grade; demineralized water;
The experimental equipment: four-necked flask, thermometer, heating stirrer, drip bottle, mortar mixer.
Now add a certain amount of TPEG polyether and demineralized water to the flask, stir and heat up to the specified temperature, first add the solution of A, then start to dropwise add the aqueous solution of AA and B and C, D with a drip bottle, and add 4- 4.5h, insulation aging 1h. The sodium hydroxide solution is neutralized to PH=6-7, and the mother liquid of the high performance water reducing agent is obtained